David,

If you don't mind me asking, how did you go about adjusting your fuel pressure regulator?  I ask because I had mine set too high, but thought it was correct.  I never could get it to run well in the lower rpm range.  When I reduced the pressure I was finally able to get the engine to run better than ever.  It ran great at high speed and would even idle smoothly down to 900 -1000 rpm.  With the manifold referenced pressure regulator, the fuel pressure will change depending on MAP.  If I'm correct, you should set it with the engine not running.  If you set it with the engine running, your actual pressures will be way too high, causing tuning issues.

 

Mark S.

 

On 4/7/07, David Leonard <wdleonard@gmail.com> wrote:

Tracy,

 

Cool, this is the first I have heard of the injector drive update and I am hopeful that it might be the key to my idle problems.  I have done a lot of fiddling and still cant beat it.  I am particularly interested to hear what kind of idle issues it fixes, to see if it sounds like mine.

 

My problem consists of constantly wandering mixture need... (the O2 bar is constantly wandering full scale without change in throttle, load, or mixture setting).   I have frequent misses, and I have to run my fuel pressure as low as my regulator can be set (about 32 psi at idle) or the problem gets worse. 

 

The weirdest thing occurs at shutdown.  I shutdown by turning off the fuel pump.  When I do that, the engine runs silky-smoothly for a second or two before stopping. 

 

That made me concerned there might be some sort of electrical interference between the fuel pump and the EC2 since they were on the same buss.  I moved the pump to a separate buss, tried a different pump, tried another buss, and installed a capacitor but none of that seemed to have any effect.

 

Do you think it would be worth sending my EC2 in for the new upgrade?

 

--

David Leonard

Turbo Rotary RV-6 N4VY
N4VY.RotaryRoster.net
www.RotaryRoster.net
leonardiniraq.blogspot.com

 

On 4/6/07, Tracy Crook <lors01@msn.com> wrote:

 

EC2 injector drive snubber update.

 

On the subject of the injector driver snubber change,  I had hoped to make it an easy to do in the field thing but it did not turn out that way.  The physical change is fairly simple (adds a single part to the board) but the change in injector drive pulse width requirement was so radical that it is beyond the current range of the injector flow rate adjustment (Mode 3).   This requires an update to the EC2 software so it has to be done here : (

 

The same thing applies to the EM2 since it determines the fuel flow by looking at the injector pulse on time.   It could not be recalibrated to compensate for the change so it's software had to be updated as well.

 

OTOH, if you are currently flying the EC2 and/or EM2 and you are happy with the way it is running, there is no pressing need to change anything.  This is not a safety of flight issue. 

 

 This change is only necessary if you are finding it impossible to get the engine to run smoothly at idle.  Note that this is not the only thing that can cause rough idle so only do this as a last resort to fix idle problems.

 

Since I only today got the EM2 software changes installed, I still do not know if there is any fuel burn improvements as a result of the snubber change.  All EC2s shipped since March 20 have this change incorporated.

 

Tracy